40. Internet Shopping In a Gallup poll, 1025 randomly selected adults were surveyed and 29% of them said that they used the Internet for shopping at least a few times a year.

a. Find the point estimate of the percentage of adults who use the Internet for shopping.

b. Find a 99% confidence interval estimate of the percentage of adults who use the Internet for shopping.

c. If a traditional retail store wants to estimate the percentage of adult Internet shoppers in order to determine the maximum impact of Internet shoppers on its sales, what percentage of Internet shoppers should be used?

Determining Sample Size. In Exercises 41–44, find the minimum sample size required to estimate a population proportion or percentage.